Electrical contactor system



Julie 10, 1947. w- LEAR 2,421,947

ELECTRICAL CONTACTOR SYSTEM Original Filed Dec. 14, 1939 INVENTOR. W/ZZ/A/V R 164/? ATTORNEY Patented June 10, 1947 ELECTRICAL CONTACTOR SYSTEM William P.:-Lear,:=l\lorth Hollywood,20alif., assign- -or, -by memo r-assignments, to :Lear, {Incorporated, Grand. Rapids, Mich, 3:3. :corporation 'of Illinois Original application December "14, 1939, "Serial No. 309,137. -Divided and this application July 2, 1943, Serial No. 493,188

2 Claims. .(Cl. '173324) 'This'invention relates to electrical contactor arrangements and more particularly relates to a novel contacton and slip ring assembly for effecting continuous electric connection with rotatable objects, such as a rotatable antenna. .Thiscase isa division of my copendingapplication Loop antennasystem, Serial No. 309,137, filedDecember 14,1939, now Patent No. 2,343,306, dated Marc-hi, i944, which 'is assigned to the .same

assignee as the present case.

In accordance with the present inventionl provide a contactor element consisting of a flexible metal strip having both ends bent over to form tongues arranged at an angle with the longitudinal axis of the contactor. Preferably, the bentover tongues of the contactor element are provided with longitudinally extending slots to obtain smoother frictional contact and a large contacting area with their cooperatin collector rings. The contactor and slip ring assembly employs flat or annular slip rings, with the contactors arranged in the same plane. Moreover, the contactors are of a shape to permit a single design of all contactors for a collector ring assembly. The contactors of the invention afford a good contact with their coacting slip rings in a most compact space with a minimum of parts, being particularly suited where flat assemblies are indicated.

Preferably, the contactor and slip ring assembly of the invention forms part of a directional loop antenna for aircraft such as disclosed in my copending application referred to hereinabove. However, it is to be understood that the contactor of the invention may be used in connection with any rotatable object having collector rings for effectin continuous electrical connections therewith. Foolproof operation is afforded despite strenuous service conditions such as encountered on aircraft in flight.

These and further features, advantages and objects of the present invention will become further apparent in the following description of a preferred embodiment thereof, illustrated in the drawing.

In the drawing:

Fig. 1 is a longitudinal sectional View through a portion of a rotatable loop antenna structure showing an embodiment of the invention contactor arrangement.

Fig. 2 is a horizontal view of the collector rings and contactors as taken on the line 2--2 of Fig. 1.

Fig. 3 is a vertical sectional view through the contactor assembly as taken on the line 3-3 of Fig. 1.

fFigAsis a; plan .view: on-an-enlarged. scale of a ;metal strip:- f or; forming the contactor.

. Fig. -5,is atop; plan view of;the,=;part ly shaped @contactor.

Figs. Grand 17 are side and perspectivevviews,

, respectively,;of the completed contactor.

Referring to -the drawing, and more .;particuused in radio direction ifinders for aircraft.

,Rotatable antenna +0 is secured to .a circular *insulationblockl lzconnected with; drive; shaft. 12

through pin and threaded coupling member l3. Coil H1 is rotatably mounted within a stationary enclosing shell 15 preferably of streamline contour. Shell i5 is preferably made of dielectric or composition material, as disclosed in my copending application referred to. Roller thrust bearing I6 is provided between shaft I2 and shell l5. Shell [5 is secured to base I! by means of screws l8. Arubber strip 20 is interposed between base H and shell 15 to absorb vibrational stresses and Weather seal the unit. Ends 20 and 2| of the windings of rotatable antenna l0 are connected with coplanar annular or flat slip rings 22 and 23, at points 24 and 25, respectively, as shown in Fig. 2.

The bottom face of circular block II is formed with two concentric annular projections 26 and 21. Projections 26, 2! are coated with a metallic surface, as by electroplating, forming collector rings 22 and 23, respectively. In the preferred embodiment projections 26, 21 are silver-plated to form closely adherent metallic layers on composition block H, which block may be of Bakelite. The silver-plated surfaces form low resistance, Well-wearing, corrosion resistant collector rings 22, 23 coacting with the stationary spring contactors 30, 30.

Contactors 30 include tongues looped over and pressed against the associated annular collectin rings 22, 23 as illustrated particularly in Fig. 3. The contactors are made of spring material, such as phosphor-bronze, and are preferably silverplated to establish eflicient electrical connection with the loop winding through collector rings 22, 2'3. Contactors 30 are shaped from a strip of metal as shown in Fig. 4. Tongues or end portions 3| have longitudinally extending slots 36, and are bent over at an angle to the longitudinal axis of middle portion 31, as clearly shown in Fig. 5. The tongues are then formed with curved tips or contacting portions 38, as illustrated in Figs. 6 and 7. Tips 38 of contactors 30 are pressed against slip rings 22, 23 as shown in Figs. 2 and 3 to afiord efiicient electrical connection with loop winding ends 20, 2|. The spring pressure of tips 38, inherent in the design and construction of contactors 30, ensures continuous and smooth electrical connection despite vibration and other stresses on the structure as encountered in flight conditions of an aircraft.

Slots 36, in the end portions of contactors '30, space the curved tips 33 from each other, providing two independent sections for equalizing the pressure exerted on slip rings 22, 23. Tongues 3| of contactors 30 are bent so as to contact with fiat slip rings 22 and 23, substantially in a tangential direction, to increase the contacting area between the contactors and the slip rings. The base of each contactor 30 is mounted slightly displaced radially with respect to collector rings 22, 23 so that the tips 38 coact with the collector rings over a relatively wide area.

The contactors 30 for both slip rings 22 and 23 are of the same shape and size. They are, however, so arranged that their contacting tongues 31 are reversely directed, as shown in Fig, 2, for elfective coaction with the collector rings. The flat rings 22, 23 are concentric and of different diameters. The reverse angular orientation of the similar contactor units 30 permits a single design of the contactors for the assembly, thus reducing the types of parts to stock for assembly or service.

It is to be understood that modifications may be made in practicing the present invention without departing from the broader principles and scope thereof, and accordingly I do not intend to be limited to the specific embodiment shown.

What is claimed is:

1. A contactor for establishing an electrical connection with a relatively movable conductor comprising a conductive strip having a body terminating in reversely bent resilient ends, each of said ends being acutely disposed with respect to said body in elevation and plan.

2. A contactor for establishing an electrical connection with a relatively movable conductor comprising a conductive strip having a body terminating in reversely bent resilient split ends, each of said ends being acutely disposed with respect to said body in elevation and plan, and each of said ends providing a convex contacting portion.

WELIAM P. LEAR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

